Function value expression¶
The function value expression holds a function instance and returns the execution result of the function.
Syntax¶
- function_value_expression
function_value_expression ::=
function_name '(' value_expression ( ',' value_expression )* ')'
| function_name '()'
Parameters¶
function_name¶
The name of a function. For more information, see Functions.
value_expression¶
An expression that returns a value used as the argument of a function. For more information, see Value expressions.
Examples¶
Use the function abs()¶
The function abs() returns the absolute value of a number.
RETURN abs(-32.4) AS f1
Return:
+------+
| f1 |
+------+
| 32.4 |
+------+
Use the function substring()¶
The function substring() returns a substring of a string.
RETURN substring("abc", 1, 1) AS f2
Return:
+----+
| f2 |
+----+
| a |
+----+
Use multiple function expressions¶
RETURN abs(-32.4) AS f1, substring("abc", 1, 1) AS f2
Return:
+------+----+
| f1 | f2 |
+------+----+
| 32.4 | a |
+------+----+
Use functions without arguments¶
RETURN date() AS currentDate
Return:
+-------------+
| currentDate |
+-------------+
| 2024-07-10 |
+-------------+